So many of them start businesses because they are able to get loans easy from the federal government. An individual that I know explained to me that he was turned down for a small business loan because he was not a minority, a woman, and not a foreigner. Yes, he's a native-born White American male.
Plus, many of the immigrants work in family businesses, of which ten to fifteen crowd into one house until one business is successful that will allow for further expansion.
Actually they tend to start small businesses with zero loans. Family owned restaurants are the favorite (as they have been for generations of immigrants for every country). Most of the immigrants I've encountered, (being a big fan of ethnic food I run into a lot) from Mexico and elsewhere, are very eager to contribute to their new country, they're better Americans than most of the natives I know. You want to be embarassed for your country, try explaining to an immigrant (who was probably at the polls half an hour before they opened they're so eagerto participate) on election Tuesday why we consider 30% voter turn out to be good.